Impeller pumps



Jan- 2, 1968 J. L SWINDALL ETAL 3,360,968

IMPELLER PUMPS Filed Jan. 2l, 1966 2 Sheets-Sheet 1 @T30 \l61 31 l@ Jan. 2, 1968 J. L. SWINDALL ETAL IMPELLER PUMPS Filed Jan. 21, 1966 2 Sheets-Sheet 2 United States Patent O 3,360,968 IMPELLER PUMPS John L. Swindall and Graham F. Clifford, Leicester, England, assignors to Samuel Pegg & Son Limited, Leicester, England, a British company Filed Jan. 21, 1966, Ser. No. 522,105 Claims priority, application Great Britain, Jan. 29, 1965,

4,146/ 65 4 Claims. (Cl. 68-189) ABSTRACT F THE DISCLOSURE A high temperature dyeing system in which hot dye liquor is circulated by an impeller pump through a kier containing goods and is made up with cool dye liquor fed from an open expansion tank by an auxiliary pump to the impeller pump, this cool liquor flowing through an annular chamber around the rotaryV seal of the impeller shaft of the impeller pump so as to cool this seal and then to the impeller chamber of the pump where it mixes with the hot liquor.

This invention relates to systems in which liquid at a high temperature is circulated by an impeller pump and into which liquid at a lower temperature is fed to make up the hot liquid to the required quantity or for other purposes.

The invention has been devised primarily in connection with a high temperature dyeing system in which hot dye liquor at a high pressure is circulated by an impeller pump through the goods to -be dyed, cooler liquor being added at required times to make up the dye concentration in the circulation liquor in compensation for the dye taken up by the goods. This make-up liquor is added in small quantity compared with the bulk of the circu lating liquor and it is most convenient therefore to arrange for it to be heated up to the dyeing temperature when it is incorporated in this bulk and circulated with the latter around or through heating means which are provided to build up and maintain the required high temperature. It is to be understood, however, that this is one example only of a system to which the present invention is applicable.

The impeller pump used in such a system, and also in analogous systems, to move the liquid at a high temperature through the system is frequently of the kind comprising a rotary impeller which is driven through a drive shaft having associated therewith sealing means which form a rotational seal between the shaft and a iixed part of the pump, e.g. the casing, through which the shaft extends into the impeller chamber.

It is an object of this invention to provide a means of combating the damaging effects which may result from the exposure of this rotational seal to the effects of the hot liquid in the impeller chamber.

To this end, in the system according to the invention, the liquid at a lower temperature is introduced into the system in the vicinity of the sealing means forming the rotational seal for the drive shaft of the pump impeller thereby to isolate or protect this seal from the effect of the hot liquid.

The invention also provides, in or for such a system, a pump comprising a rotary impeller which is driven through a drive shaft having associated therewith sealing means which form a rotational seal between the shaft and a fixed part of the pump through which the shaft extends into the impeller chamber, and means defining around the sealing means an annular compartment having an inlet for con- 3,360,968 Patented Jan. 2, 1968 nection to the supply of liquid at a low temperature, and an outlet for connection to the liquid at a high temperature in the system, whereby in operation the liquid at a low temperature flows into the annular compartment around and in contact with the sealing means so as to cool the latter, before it is fed to the liquid at a high temperature.

An example of a system according to the invention and an example of a pump for use therein will now be described with reference to the accompanying drawings.

In the drawings:

' FIGURE l is a diagrammatic illustration of a dyeing system,

FIGURE 2 is a vertical cross section through the pump of this example, and

FIGURE 3 is a detailed cross section through part of the pump illustrated in FIGURE 2.

Referring first to FIGURE l of the drawings, here there is shown a high temperature dyeing system including a kier 1 in which the goods to be dyed-a cone of thread in this example-are disposed. The kier 1 has an inlet 2 communicating with a vertical perforated tube 3 on which the thread cone is supported, and an outlet 4 in the botton of the kier, the inlet and outlet being connected to the two sides of an impeller pump 5. The kier 1 contains a steam-0perated heating coil 6 the function of which is to heat the dye liquor circulated by the pump 5 through the closed circuit, formed by the kier and the pump and pressurised as described below, to a temperature of the order of 2v80-300 F.

Connected to the upper end of the kier 1 by a restricted overflow pipe 7, which incorporates a condenser 8 cooled by a separate cold water supply to 140, is an expansion tank 9. This expansion tank contains a reservoir of dye liquor and is connected by an outlet pipe 10 to the inlet side of the pump 5, this pipe 10 including an auxiliary pump 11 which pressurises the dye liquor fed from the expansion tank 9 and advances it to the pump 5. The system also includes various non-return valves 12.

In operation, dye liquor is continuously circulated by the pump 5 through the kier 1, and is maintained at the required temperature, e.g. 290 F., by the heater 6. This liquor is made up with liquor fed into the closed circuit from the expansion tank 9 by the auxiliary pump 11, i.e. with liquor at the lower temperature. At the same time, the pump 11 pressurises the liquor in the circuit to prevent it flashing-off into steam at the high temperature prevailing in the circuit.

The pump 5 is of the form illustrated in FIGURES 2 and 3 of the drawings. This pump is capable of reversing the direction of liquor flow and is basically of the construction described in our prior United States Letters Patent No. 3,183,837. It comprises three sections, viz. a motor block 13 containing a motor for driving the pump, an impeller unit 14 and a control section 15.

The motor in the -block 1 drives a shaft 16 which extends through the adjacent rear wall 17 of the fixed cylindrical casing of the impeller unit 14 and carries a centrifugal impeller 18. The impeller is formed with an annular section 18a accommodated in a complementary recess in the wall 17, and with a sleeve 18h which extends out through this wall and is keyed on the shaft 16. The cylindrical wall 19 of the casing of the impeller unit 14 is hollow and is divided by two radial partitions (not shown) into two liquid headers 20 and 21 cornmunicating respectively with two upwardly extending liquid-flow service conduits, one of which is shown at 22. Mounted in the impeller casing is a cylindrical hollow valve shell 23 which is turnable through a stem 24 by a valve-adjusting hand lever (not shown) on the control section 15. This valve shell has an internal partition 23a which divides it into an outlet chamber A containing the impeller 18, and an inlet chamber B, and which is formed with an apertured boss coaxial with the impeller. The tubular wall of the shell 23 is formed with two arcuate slots 24 and 25 in the chambers A and B respectively. The cylindrical Wall 19 of the im-peller casing is provided with two pairs of ports (not shown) with which the two slots respectively cooperate, each pair being disposed around one of the chambers A and B, and the two ports of each pair opening into the headers 20 and 21 respectively.

In operation, with the valve shell in the position indicated, dye liquor is drawn down the service conduit communicating with the header 21 into the latter and then through the opening provided by the slot 2S and the cooperating port into the chamber B. The liquor then passes through the apertured partition 23a into the chamber A and thence through the opening provided by the slot 24- and the co-operating port into the header 20 from where it leaves the pump through the associated service conduit. The liquor flow `path is indicated by the arrows C in the drawings.

To reverse the direction of fiow, the valve shell is turned through 180 so that different ports in the casing are brought into register with the valve slots 24, 25. Thus, the liquor enters chamber B from the header 21 and is expelled from chamber A into the header 20. The path of flow is indicated by the arrows D.

Referring particularly to FIGURE 3 of the drawings, the rear wall 17 of the impeller casing is formed as a boss which provides the aforesaid recess accommodating the annular section 18a of the impeller, and the aperture in this boss through which the driving shaft 16 and the sleeve 13b emerge, is provided with a gland 26 to support part of the rotational sealing means for the drive shaft sleeve 18h. The sealing means are in two parts, viz. a carbon collar 27 disposed around the sleeve 18h and secured to the gland 26 through an O ring 28, and a stainless steel sealing sleeve 29 which is tted around the said sleeve with an O ring 30 therebetween and the end face of which bears against the opposed end face of the carbon collar 27. The confronting faces of the collar and sealing sleeve are maintained in contact by a suitably calibrated compression spring 31 arranged between the opposite face of this sealing sleeve and the rear part of the impeller 18.

In pursuance of the present invention arrangements are made to direct the cooler make-up liquor into the hot liquor circuit via the pump and in such a way that it is used to protect the rotational sealing means from the effects of this hot liquor. To this end, an inlet 32 is formed in the boss of the casing rear wall 17, and a pipe 33 connects this inlet to the supply of liquid at a low temperature in the system in which the pump is to be used. A dishshaped baffle plate 34 is fastened to the rear wall 17 inside the boss thereof, with its edge abutting against this wall in sealing fashion, by means of bolts 35 which also secure the gland Z6 in position, there being suitable spacing bushes between the plate 34 and the gland.

The baffle plate, which is coaxial with the shaft 16 and sleeve 181:, is formed with a central aperture in which the sleeve 29 is located, and is so dimensioned that there is a small clearance between the the edge defining the aperture and the sealing sleeve 29. There is accordingly formed between the rear wall 17 of the impeller casing and the baffle plate 34 an annular compartment into which the cool liquor flows from the pipe 33. The liquor then flows over the carbon collar 27, the sealing sleeve 29 and their contacting faces and passes through the narrow annular gap between the `baflie plate 34 and the sealing sleeve into the compartment defined by the annular section 18a of the impeller behind the latter. From here the liquor flows through apertures 36 drilled in the rear part of the impeller into the impeller chamber A where it mixes with the hot liquor being circulated by the pump.

Thus, any hot liquor moved by the impeller will be kept clear of the sealing means by the inilowing cool liquor. This means that the sealing means will always run cool and a liquid film will form between the carbon collar and the sealing sleeve to lubricate the seal and discourage wear, such as might occur if hot liquor contacted the sealing means and became exposed to the atmospheric pressure at the other side of the means, and so caused dry running.

A primary advantage of the present invention is that the sealing means are kept immersed in cool liquid directly at the entrance of the latter into the system, so that it will remain at the temperature of the expansion tank and be independent of the operating temperature prevailing in the main closed circuit.

It will also be seen that the required result is brought about sim-ply and without the need for any elaborate water cooled, or pressure-balanced, sealing means.

We claim:

1. A system comprising a circuit for the circulation through it of liquid at a high temperature, an impeller pump incorporated in this circuit for circulating liquid through the latter, the impeller pump having an internal chamber, an impeller mounted in this chamber, a drive shaft which extends through a fixed part of the pump into the impeller chamber and is connected to the impeller for driving the latter, sealing means forming a rotational seal between the drive shaft and the said fixed part of the casing, an-d supply means including a single set of connections for supplying all of the liquid to the circuit at a lower temperature in the vicinity of the sealing means whereby the sealing means is protected from the effect of the hot liquid.

2. A system in accordance with claim 1 wherein said liquid comprises a dye liquor.

3. A high temperature dyeing system comprising a circuit including a vessel for receiving goods to be dyed and a main impeller pump for circulating dye liquor iat a high temperature through the vessel; said impeller pump having an internal chamber, an impeller mounted in this chamber, a drive shaft which extends through a fixed part of the pump and is connected to the impeller for driving the lat-ter, and rotational sealing means between the drive shaft and the said fixed part of the pump; means defining around the sealing means an annular compartment having an outlet which is in communication with the impeller chamber, and an inlet; an open expansion vessel connected to this inlet for holding dye liquor at a lower temperature; and an auxiliary pump connected between the expansion vessel and the inlet for forwarding dye liquor from the expansion tank to the annular compartment, whereby in operation cool dye liquor from the expansion tank flows through the annular compartment to cool the sealing means and then to the impeller chamber where it mixes with the hot dye liquor being circulated by the pump.

4. An impeller pump comprising a casing defining a chamber, a rotary impeller mounted in this chamber, a drive shaft which extends through a wall of the pump casing into the impeller chamber and is connected to the impeller for driving the latter, sealing means which form a rotational seal between the drive shaft and the said wall of the pump casing, means defining around the sealing means an annular compartment which is disposed behind the impeller between the said wall and the latter and has an inlet for connection to a supply of liquid at a low temperature, and an outlet in communication by means of apertures formed in the impeller with the impeller chamber through which liquid at a high temperature flows in operation, characterized in that the inlet for the liquid at a low temperature is formed in the said wall of the casing adjacent t-he drive shaft, and a dishform baie plate is mounted inside the casing with its edge `abutting in sealing fashion against the said wall so as to dene with the Wall the annular compartment around the sealing means into which the said inlet opens, this bale plate having a central laperture in which a part of the sealing means is located with a small clearance, `whereby in operation the liquid at a low temperature flows from the inlet into the annular compartment, through the restricted annular gap between the baHe plate and the adjacent part of the sealing means so as to cool the latter and through the yapertures in the impeller into the impeller chamber where it mixes with the liquid at a high temperature being pumped by the pump.

6 References Cited UNITED STATES PATENTS 2,677,328 5/1954 vifek 103-111 2,824,759 2/1958 Tracy 103-111 3,076,412 2/1963 Horker et a1 10s-111 3,185,101 5/1965 Brooks et a1. 103-111 3,213,798 10/1965 Carsweu 103-111 3,199,752 `:3/1965 Casse 68-189 FOREIGN PATENTS 514,045 2/1955 Italy.

HENRY F. RADUAZO, Primary Examiner. 

